What capacity do I need in a rolling teacher tote?

Most teacher-focused rolling totes land in the 30L to 50L range with a dedicated 15.6" laptop compartment plus an accordion file section. Discussions in r/Teachers and r/teaching emphasize must-haves like a padded laptop pouch, water bottle pockets, and a detachable dolly so the bag can be carried like a tote when not rolling. If you transport binders, manipulatives, or grading stacks between rooms, look for explicit accordion-file organization rather than just a single large compartment.